634 chapter 67
Above-knee limb with knee joint (for older children and adults)
Adapted from the
OHI Manual: Simple
Above-knee Prosthesis
Manufacture. (Write for
the complete manual. For
address, see p. 641.)
Note: This is a simple
design for a knee joint.
Knee joints that work
well are hard to make
and you may need
to experiment a lot.
Perhaps you can re-use
a joint from an old limb
that is not being used.
SIDE VIEW
Socket piece of
leather
(see next page).
(It can also be
made of plaster,
resin, or wood.)
support strips
of metal
FRONT VIEW
To help keep knee
from bending when
weight is on it,
stretch a piece
of rubber across
front of knee.
flat metal bars
knee joint
wood
leather
strip of
car tire
inner tube
wood and
rubber foot
(for very short
stumps only)
Making the knee joint:
6 cm.
2.5 2.5 1 cm.
{
bolt
1. Mark and
round the
top of the
post.
2. Drill
hole
at exact
center of
circle.
3. Weld or
rivet angle
piece at
right angle.
(Use flat
metal bar.)
4. Round
back of
post.
6. Ledge
prevents knee
from bending
backward.
Small strip of
car tire acts
as cushion.
5. Drill hole in
post and attach
bolt with wire (to
lock knee straight,
when necessary).
7. Add an
angled piece
to allow joint to
stop in a squatting
position.
FEET
Putting feet on artificial legs makes them look better (with shoes, sandals, or
boots). Also, the wide base helps prevent the leg from sinking into mud or sand.
A well-made, flexible foot can make walking easier. Here are 2 possibilities.
wood block
(Use strong
wood that will
not crack.)
leg pole
old car
tire (one
piece)
lightweight
spongy rubber
Note: By putting the pole
through the foot, if the foot
breaks off the person can
keep walking.
The sponge rubber
over the heel and toe
lets the foot bend
for smoother walking.
To mount
a foot on a
plastic PVC
tube, use a
metal pipe
base like
this.
A foot can also be made for a metal-
rod leg. Here is one possibility.
metal
plate
weld
Bolts should
pass through
all but last
layer of
rubber.
Leave open
space above
bottom
sole for
flexible
heel.
3 or 4 layers of car tire, cut to
allow flexibility of toes and heel
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